The Hobbit has a lighter feel, as in, not the high medieval drama of LOTR with epic battles etc, but is a fairy story, so the look should reflect this, but at the same time be recognizably Middle Earth, it has some of the darkness of LOTR in places but its mostly about a little Hobbit and bumbling Dwarves. So do you have a brighter lighter tone or dark and moody tone? Its a balancing act. Perhaps the colour palette will start bright and golden and slowly edge towards the blue scale and become darker? Maybe up to Rivendell the skies will be blue and the light golden? perhaps the journey afterwards will become wet and miserable dark and dangerous towards Trollshaws? its just my supposition.